Vulvodynia is chronic idiopathic (or unexplained) pain of the external genitalia (vulva) that is estimated to affect 8% of American women by the age of 40. The highest incidence occurs in women during their early reproductive ages, and the onset of vulvodynia may occur during adolescence with patients reporting pain at first tampon use. While causes of vulvodynia are largely unknown, it is believed to be the result of an altered immune-inflammatory response mechanism. Our previous research supports this hypothesis by showing that women who develop vulvodynia are approximately 2 times more likely to have suffered from allergies or allergic responses prior to vulvodynia onset. Given that many women diagnosed with vulvodynia have evidence of pain with first tampon use during adolescence, women at greatest risk of vulvodynia may have had their immune systems compromised either prenatally or at birth, early in their life course, or both. Documenting health-related events across the life course would allow for the assessment of conditions or treatments that influence immune function, or are markers of compromised immune health. We propose to conduct a nested case-control study within an existing cohort of all Swedish females born between 1981 and 1996 already assembled using Swedish National Registry data for another ongoing initiative. For this nested study, all women with a specific vulvodynia diagnosis (ICD code N76.3) between 2012 and 2016 (n=~3500 women) will comprise cases, and each case will be matched to a control from the same birth year with no history of vulvar pain as of the case?s date of diagnosis. Our aims are to assess the effect of a) Maternal and neonatal events including maternal prenatal antibiotic use for chorioamnionitis, Group B streptococcal infection or premature rupture of membranes, cesarean section deliveries, and neonatal hospitalizations; b) Immune-specific conditions manifesting as deficient, autoimmune, and overactive from infancy up until onset of vulvodynia or a comparable time period among controls, and c) Psychiatric conditions from adolescence up until onset of vulvodynia and a comparable time period among controls, on the risk of vulvodynia in women between the ages of 15 and 35. Precursors to vulvar pain present at adolescence indicate a need to take a life course approach toward understanding the pathogenic mechanisms that underlie vulvodynia. Carrying out research across the lifespan can identify immune related events during critical risk periods, and its impact could lead to more careful screening based on medical histories and potential interventions to prevent or mitigate this debilitating condition.